<template>
  <div id="home">
    <nav-bar class="home-nav"><div slot="center">购物街</div></nav-bar>
    <tab-control :titles="['流行','新款','精选']"
                 @tabClick="tabClick"
                 ref="tabControl1" class="tab-control"
                 v-show="isTabFixed"></tab-control>
    <scroll class="content"
            ref="scroll"
            :probe-type="3"
            @scroll="contentScroll"
            :pull-up-load="true"
            @pullingUp="loadMore">
      <home-swiper :banners="banners" @swiperImageLoad="swiperImageLoad"></home-swiper>
      <recommend-view :recommends="recommends"></recommend-view>
      <feature-view/>
      <tab-control :titles="['流行','新款','精选']"
                   @tabClick="tabClick"
                   ref="tabControl2"></tab-control>
      <goods-list :goods="showGoods"/>
    </scroll>
    <back-top @click.native="backClick" v-show="isShowBackTop"/>
  </div>
</template>

<script>
  import HomeSwiper from './childComps/HomeSwiper.vue'
  import RecommendView from './childComps/RecommendView'
  import FeatureView from './childComps/FeatureView'

  import NavBar from 'components/common/navbar/NavBar.vue'
  import TabControl from 'components/content/tabControl/TabControl.vue'
  import GoodsList from 'components/content/goods/GoodsList.vue'
  import Scroll from 'components/common/scroll/Scroll.vue'


  import {getHomeMultidata, getHomeGoods} from "network/home";
  import {itemListenerMixin, backTopMixin} from "common/mixin";

  export default {
    name: "Home",
    components: {
      NavBar,
      HomeSwiper,
      RecommendView,
      FeatureView,
      TabControl,
      GoodsList,
      Scroll
    },
    mixins: [itemListenerMixin, backTopMixin],
    data() {
      return {
        banners: [],
        recommends: [],
        goods: {
          'pop': {page: 0, list: []},
          'new': {page: 0, list: []},
          'sell': {page: 0, list: []},
        },
        currentType: 'pop',
        tabOffsetTop: 0,
        isTabFixed: false,
        saveY: 1000
      }
    },
    computed: {
      showGoods() {
        return this.goods[this.currentType].list
      }
    },
    created() {
      //请求多个数据
      this.getHomeMultidata()

      //请求商品数据
      this.getHomeGoods('pop')
      this.getHomeGoods('new')
      this.getHomeGoods('sell')


    },
    mounted() {
    },
    methods: {
      /**
       * 事件监听相关方法
       */

      tabClick(index) {
        switch(index) {
          case 0:
            this.currentType = 'pop'
            break
          case 1:
            this.currentType = 'new'
            break
          case 2:
            this.currentType = 'sell'
            break
        }
        this.$refs.tabControl1.currentIndex = index
        this.$refs.tabControl2.currentIndex = index
      },

      contentScroll(position) {
        //判断BackTop是否显示
        this.isShowBackTop = position.y < -1000

        //决定tabControl是否吸顶
        this.isTabFixed = position.y < -this.tabOffsetTop
      },
      loadMore() {
        this.getHomeGoods(this.currentType)
      },
      swiperImageLoad() {
        //获取tabControl的offsetTop
        //所有组件都有一个$el,用于获取组件的元素
        this.tabOffsetTop = this.$refs.tabControl2.$el.offsetTop;
      },
      /**
       *
       * 网络请求相关方法
       */
      getHomeMultidata() {
        getHomeMultidata().then(res => {
          this.banners = res.data.banner.list;
          this.recommends = res.data.recommend.list;
        })
      },
      getHomeGoods(type) {
        const page = this.goods[type].page + 1
        getHomeGoods(type, page).then(res => {
          this.goods[type].list.push(...res.data.list)
          this.goods[type].page += 1

          //完成下拉加载更多
          this.$refs.scroll.finishPullUp()
        })
      }
    },
    activated() {
      this.$refs.scroll.scrollTo(0, this.saveY, 0)
      this.$refs.scroll.refresh()
    },
    deactivated() {
      //保存Y值
      this.saveY = this.$refs.scroll.getScrollY()

      //取消全局事件监听
      this.$bus.$off('itemImageLoad', this.itemImgListener)
    }


  }
</script>
<!--scoped作用域-->
<style scoped>
  #home {
    /*padding-top: 44px;*/
    height: 100vh;
    position: relative;
  }
  .tab-control {
    position: relative;
    z-index: 9;
  }
  .home-nav {
    background-color: var(--color-tint);
    color: #fff;
    font-size: 18px;
  }



  .content {
    /*height: calc(100% - 93px);*/
    overflow: hidden;
    position: absolute;
    top: 44px;
    bottom: 49px;
    left: 0;
    right: 0;
  }
</style>
